Upgrades for 402 LS

[David Pozzi]

On the One Lap Camaro I have to watch out to not open the throttle too wide or the engine lays down a little at low speeds. Penny didn't do that at all but perhaps throttle by wire has something to do with it.



The FAST 102 might be a good way to go. Does it fit the AFR ports? It's $400+ to port my current manifold, so maybe I could put that money towards a new intake. and a 95mm TB. Does the FAST 102 benefit from any porting work?

[Damn True]

See how he skipped your question? See that?

A conspicuous omission to be sure.

I know what options are available.

Build it David. Build it.

[Steve1968LS2]

On the One Lap Camaro I have to watch out to not open the throttle too wide or the engine lays down a little at low speeds. Penny didn't do that at all but perhaps throttle by wire has something to do with it.

The FAST 102 might be a good way to go. Does it fit the AFR ports? It's $400+ to port my current manifold, so maybe I could put that money towards a new intake. and a 95mm TB. Does the FAST 102 benefit from any porting work?

Yea, the now 102mm will work fine.. I can get you a discount on the intake and the rest is just plug and play.

You can port your own intake.. especially with your skills. Not "hard" just time consuming.

All intakes benefit.. but my guess is that the 102 will be good out of the box considering the heads on the engine.

Mike Norris is the guy to talk to about massaging your TB.

[Gandalf]

Call Charlie at RPM Motors. He's a well respected LSx engine builder and tuner, esp in the Corvette community.

G.

[JMarsa]

I can't see any potential work being worth the time or $$.

That's a 8K motor to recreate and you're practically at 500 RWHP. I've studied the dyno section of ls1tech for years and it takes a lot of money to get 500 RWHP on gen III technology. The new LS3s are cheaper to get there.

Cam swap $500 in parts.
Head milling + $75 gaskets and new head bolts
Intake - $500+
TB Port - $125 for 10HP?

Read any of Tony Mamo's posts...these are the details that get you the magic number but the investment is too much in my opinion. A new tune would probably move the power around for effectively than new parts.

--JMarsa

[David Pozzi]

JMarsa,
New tune?
Are you saying I can have the ECM tuned and get more power? It's already been dyno tuned.
A new cam costs $500? Why?
I won't mill the heads, not worth it.
TBI port, that's a lot for 10hp, but it looks cheaper than the other choices.

The intake and TB has the most potential for the money. I'd have the old one to sell to offset buying a new one. I can port match or smooth up a new intake myself, just haven't done an LS intake before.

If the TB got me 10hp and intake got me 20, that's 30 hp, that would put me right at 600hp. If that could be done with next to no loss of low end it is sounding good. A little more cam and who knows?

I may not decide to do it, but I need to hear my options now, while the engine is still out of the car. I have more reading up to do on these engines.

I didn't want to confuse things by bringing this up, but I also have another engine that could use the old FAST 90 intake and AFR heads, and I could buy new parts for the 402, like new intake and ported LS3 type heads.

[JMarsa]

Usually a dyno tune will get you top numbers. But you can have a tuner spend a day with the can on the street (forgot you don't have the engine installed yet) and he can tweak the timing and fuel to slide around the power curve a bit.

Selling parts like an intake to offset the cost of new ones will bring you about .75 on the dollar. It's not like they wear out and there's strong demand.

Usually a cam kit is purchased, cam, lifters and pushrods (maybe you won't need new ones) here's some examples:

http://www.thunderracing.com/catalog...&vid=7&pcid=51


Instead of an intake I would go with a UD pulley and possibly a EWP. As said earlier, it doesn't look like your air limited. Good headers can made a difference, but it depends on the car, on a 'vette you can see a 10-15HP variance between the vendors.

On ls1tech this guy is local to me: 'allngn_c5' he's spent a ton of dough going from 490 RWHP to:

LS2 402 - 541 rwhp 505 rwtq Tuned by Vengeance Racing
TFS 215's (59cc) Custom Cam, 1 7/8 ARH, Ported FAST 92, UD Pully, EWP

--JMarsa

[WS6]

If your current FAST 90 isn't ported, get that done. I missed that and thought you had the LS2 intake on the engine. The differences between your engine and the vengeance 402 aren't worth the efforts. They got nice peak numbers out of the car but the torque isn't much broader than your curve. It's moved up in the RPM band a tad but holds on longer. Better intake will be the cheapest way to extend your torque band into the upper RPMs which is the biggest advantage that engine has over your current setup.

[David Pozzi]

Sorry I don't fully speak LS yet. What is "possibly a EWP" ?
Thanks for the info guys!
David

[JMarsa]

:-) electric water pump, Under drive pulley = UD

--JMarsa

[madmax]

Another thing that would help would be trading out the FAST 90mm intake for thier brand new 102mm cathedral port intake.

I've been hearing that the jury is still out on the 102 and may not make that much of a difference over the 92, especially on a motor like this (may be different on ultra-high hp motors). From what I hear little to no portwork is possible on that manifold.

Like WS6 said, if the 90 isn't ported, do it. I know that Jeremy Formato (great tuner down here in FL) is getting around 18rwhp/tq across the entire band from ported 92s (not sure about the 90). He's currently running a special on both TBs and manifolds for like $375 or $400 and does excellent work.

An electric WP would definately free up some horespower but are also a little pricey, but at this stage there isn't much left to do. The port would get you damn close to 500whp, and the pump over it.

This is from what very little I know lurking on various LSx sites.

Max

[David Pozzi]

Thanks Max. I'm lurking a lot too!

[madmax]

http://www.ls1tech.com/forums/12670469-post20.html

There are a couple LSXR numbers. Looks like it is good for about 12-15hp over a stock LS3, with no portwork possible (hardly impressive)

Dyno:
http://www.ls1tech.com/forums/12356431-post22.html

So... you can make those kinds of gains by porting a stock intake, and even more with ported FAST 92 (again, I don't have any info regarding the 90).

Here is a link to the Formato specials: looks like a FAST + TB is $375. I was wrong about the numbers; he is getting 15-17/18-21 on a stock LS2 manifold. Not bad.


http://forums.corvetteforum.com/c6-z...g-special.html

[madmax]

David -

Been reading a lot of good things about the 102, especially on LS2s. I'll try and dig up some links, but the general consensus seems to be that it flows like a champ and would be great for your application. I know this is contrary to some of the early reports I posted... just trying to get you some good info.

Max